Summary: This research focuses on the quantitative analysis and characterization of the chemical components in vaccines including 2-phenoxyethanol. 2-Phenoxyethanol is used as a preservative in vaccines including Hepatitis, Polio, and DTaP(Diphtheria and Tetanus Toxoids and Acellular Pertussis). For these products, this laboratory has modified the USP<341> Antimicrobial Agents method to use in the quantitation of 2-phenoxyethanol. Current work includes the validation of this packed column GC method under ICH guidelines. Future research will involve the development of a capillary GC method resulting in greater column efficiency and accuracy.